Currently the navigation menu content is only positioned absolutely on breakpoints 'md:' and above. The same applies to auto width.
On smaller widths the content starts to push around the surrounding links as well as it's trigger link because it enters the normal document flow.
When applying the position absolute permanently, the 100% width does not work on any width lower than 'md:'. That's why we also have to use auto width without the 'md:' breakpoint restriction.

I have not found an issue that raised this problem. Since it's such a small change I thought it might not need it. I can create one and we can discuss the normal behavior if that is not the case.

Here is an example from the currentNavigation Menu component demo